Yes , exposure to dust can also be a factor and obviously from what you have explained there is a lot of suspended particles in the air. This is a very potential site for bacteria,viruses and fungus to thrive. So the chances are that you have an infection which has lead to swelling of lymphnode.
Yes, you can warn others to atleast cover their noses and mouth while working in such a place. Also I would suggest you to avoid staying in such a place for longer periods(more than10 hours).If you have to, atleast try to sleep somewhere else.
The anti inflammatory medicine is supposed to reduce the inflammation i.e. subside the swelling but if there is an infection persisting even in a moderate degree it won't be completely effective unless given with antibiotics in case of bacteria. However, what you can do is -
- Keep your nose and mouth covered while working
- Take the antiinflammotry medicine for 2 days (not more than that).You can take Brufen or Naproxen at an interval of 12 hours after meals.
- Warm saline gargles should be done every 4 hourly.
If inspite of all these you still have a sore throat or the lymphnode swelling,it means that specific medication is needed.Then, you need to consult a doctor and do mention about the treatment that was already done. Hope this was helpful.